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138,640

138,640 is a composite number, even.

This number doesn't have a permanent NumberWiki page yet — what you see below is computed live. Pages get added to the permanent index when they're notable (years, primes, curated, etc.).

138,640 (one hundred thirty-eight thousand six hundred forty) is an even 6-digit number. It is a composite number with 20 divisors, and factors as 2⁴ × 5 × 1,733. Its proper divisors sum to 183,884, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x21D90.

Abundant Number Gapful Number Odious Number Pernicious Number Recamán's Sequence Refactorable Number Semiperfect Number

Interestingness

Properties

Parity
Even
Digit count
6
Digit sum
22
Digit product
0
Digital root
4
Palindrome
No
Bit width
18 bits
Reversed
46,831
Recamán's sequence
a(491,547) = 138,640
Square (n²)
19,221,049,600
Cube (n³)
2,664,806,316,544,000
Divisor count
20
σ(n) — sum of divisors
322,524
φ(n) — Euler's totient
55,424
Sum of prime factors
1,746

Primality

Prime factorization: 2 4 × 5 × 1733

Nearest primes: 138,637 (−3) · 138,641 (+1)

Divisors & multiples

All divisors (20)
1 · 2 · 4 · 5 · 8 · 10 · 16 · 20 · 40 · 80 · 1733 · 3466 · 6932 · 8665 · 13864 · 17330 · 27728 · 34660 · 69320 (half) · 138640
Aliquot sum (sum of proper divisors): 183,884
Factor pairs (a × b = 138,640)
1 × 138640
2 × 69320
4 × 34660
5 × 27728
8 × 17330
10 × 13864
16 × 8665
20 × 6932
40 × 3466
80 × 1733
First multiples
138,640 · 277,280 (double) · 415,920 · 554,560 · 693,200 · 831,840 · 970,480 · 1,109,120 · 1,247,760 · 1,386,400

Sums & aliquot sequence

As a sum of two squares: 16² + 372² = 236² + 288²
As consecutive integers: 27,726 + 27,727 + 27,728 + 27,729 + 27,730 4,317 + 4,318 + … + 4,348 787 + 788 + … + 946
Aliquot sequence: 138,640 183,884 137,920 191,264 196,816 184,546 97,658 69,958 56,762 29,530 23,642 11,824 11,116 11,172 20,748 41,972 42,028 — unresolved within range

Continued fraction of √n

√138,640 = [372; (2, 1, 9, 1, 4, 1, 1, 1, 1, 3, 2, 2, 1, 1, 4, 2, 1, 7, 1, 2, 9, 2, 4, 1, …)]

Representations

In words
one hundred thirty-eight thousand six hundred forty
Ordinal
138640th
Binary
100001110110010000
Octal
416620
Hexadecimal
0x21D90
Base64
Ah2Q
One's complement
4,294,828,655 (32-bit)
Scientific notation
1.3864 × 10⁵
As a duration
138,640 s = 1 day, 14 hours, 30 minutes, 40 seconds
In other bases
ternary (3) 21001011211
quaternary (4) 201312100
quinary (5) 13414030
senary (6) 2545504
septenary (7) 1115125
nonary (9) 231154
undecimal (11) 95187
duodecimal (12) 68294
tridecimal (13) 4b148
tetradecimal (14) 3874c
pentadecimal (15) 2b12a

As an angle

138,640° = 385 × 360° + 40°
40° ≈ 0.698 rad
Compass bearing: NE (northeast)

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋 𒌋𒌋𒌋𒌋
Egyptian hieroglyphic
𓆐𓂍𓂍𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
Greek (Milesian)
͵ρληχμʹ
Mayan (base 20)
𝋱·𝋦·𝋬·𝋠
Chinese
一十三萬八千六百四十
Chinese (financial)
壹拾參萬捌仟陸佰肆拾
In other modern scripts
Eastern Arabic ١٣٨٦٤٠ Devanagari १३८६४० Bengali ১৩৮৬৪০ Tamil ௧௩௮௬௪௦ Thai ๑๓๘๖๔๐ Tibetan ༡༣༨༦༤༠ Khmer ១៣៨៦៤០ Lao ໑໓໘໖໔໐ Burmese ၁၃၈၆၄၀

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 138640, here are decompositions:

  • 3 + 138637 = 138640
  • 11 + 138629 = 138640
  • 23 + 138617 = 138640
  • 41 + 138599 = 138640
  • 53 + 138587 = 138640
  • 59 + 138581 = 138640
  • 71 + 138569 = 138640
  • 179 + 138461 = 138640

Showing the first eight; more decompositions exist.

Unicode codepoint
𡶐
CJK Unified Ideograph-21D90
U+21D90
Other letter (Lo)

UTF-8 encoding: F0 A1 B6 90 (4 bytes).

Hex color
#021D90
RGB(2, 29, 144)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.2.29.144.

Address
0.2.29.144
Class
reserved
IPv4-mapped IPv6
::ffff:0.2.29.144

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Possible US patent number

This number falls in the range of US utility patent numbers. If it's a patent, it would be issued as US 138,640 and was likely granted around 1872.

Patent numbers below 100,000 are excluded as too ambiguous; modern numbering currently reaches roughly 12.5 million.

Position in π

The digit sequence 138640 first appears in π at position 143,770 of the decimal expansion (the 143,770ordinal-suffix:th digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.

Related reading